Method of making flexible metallic bellows



March 3, 1936.

M. H. WARD METHOD OF MAKING FLEXIBLE METALLIC BELLOWS Filed Aug. 31, 1932 INVENTOR I ATTORNEYS mum Patente't'l Mar. 3, 1936 LIETHOD OF MAKING FLEXIBLE METALLIC BELLOWS Marshall 1:. Ward, rinses, 001111., alsimor a; Bridgeport Brass Company, Bridgeport, Conn, aacorporation oi Connecticut Application August 31, 1932, Serial No. 831,113

- Claims; (01. 113-410) This invention relates to a method of making flexible metallic bellows and one object of the invention is the provision of a flexible metallic bellows of comparatively small diameter and having a relatively large number of folds or convolutions and also having an annular locating shoulder and lateral flange.- Such a bellows is adapted primarily for certain specific installations and assemblies.

Another object of this invention resides in the method of producing such a bellows whereby bellows may be. manuiactured on a commercial scale to produce asatisfactory and practical article with a minimum amount of breakage and wastage. This-method broadly stated includes subjecting a metallic blank to a plurality of draw-.

of the large cup end into a lateral annular flange by spinning or otherwise and then forming a plurality of bellows folds or convolutions in the reduced body portion of the tube.

It is to be especially understood that while I have stated that this invention is designed primarily for the purpose of forming bellows of relatively narrow diameter and having a plurality of bellows folds or ,convolutions that the method or process may be used toform similar articles of diflerent dimension and construction. To the accomplishment of the foregoing and such other objects as may hereinafter appear, this invention consists in the construction, combination and arrangement of parts and also the method hereinafter described and then sought to be deflned in the appended claims, reference being bad to the accompanying drawing forming a part hereof and which shows, merely'for the purpose of illustrative disclosure, a preferred embodiment of my invention, it being expressly understood. however, that various changes may be made in practice within the scope of the claims without digressing from my inventive idea.

In the drawing- 7 Figure 1 represents a side elevational view of the cup or blank with which the operation starts. Figure 2 is a similar view after the first draw.

Figure 3 is a similar view after a plurality of" additional draws.

Figure 4 is asimilar view after the drawn tube has been trimmed to an accurate length.

pletely formed article after all Figure 5 is a similar view after the' flrst reducing operation.

Figure 6' is a similar view. after a plurality of additional reducing operations. Figure 7 isaviewsimilartol isureiiafterthe 5 enlarged cupped end is trimmed down to proper length.

Figure 8 is a similar view after the upper portion of the large cupped end has been spun out-. wardly to form a lateral annular flange. 1o

' Figure 9 is a side elevatlonal view of a 'comthe operations have been completed;

The operation starts with a cup I of suitable material of proper thickness. This cup is sub- 15 iacted to a plurality of drawing operations, 2 indicating the cup at the end of the first draw and {indicating the tube at the end of the last draw. The tube is annealed between each draw and after the last draw shown in Figure 3 is trimmed 20 to accurate length as indicated by 4.

After these drawing operations have been completed and the tube trimmed as shown in Figure 4, it is subjected to a plurality of reducing operations whereby the main or body part of the tube 25 is reduced. The result of the flrst of such operations is illustrated in Figure 5 where 5 designates the reduced body portion and i the unreduced end portion which forms a large cupped end. Alter a plurality of such operations the tube has 30 the form shown in Figure 6, wherein 'i designates the 'elongated reduced body and 8 the large cupped end. This cup end 8 is trimmed until the tube as a whole has the appearance shown in Figure '1, that is, with the elongated reduced body 35 portion 9 and the large cup end l0 having the annular shoulder I l therebetween.

This tube is then subjected to a spinning opera- .tion whereby the upper portion of the cupped end 7 One form of such machine is illustrated in my 5:

copending application Serial Number 334,454, flied Ja'nuary'23, 1929, which has become Patent No. 1,951,381, granted March 20, 1934, in which the interior of the tube is subjected to fluid pres-- sure while held between spaced and movable die 55 or forming members. Axial pressure is applied to one end of the tube while the fluid pressure is maintained and as the spaced movable die members are collapsed the bellows folds are formed and at the completion of the operation the article has-the appearance shown in Figure 9, where It represents the bottom or foot of the bellows, which is of the same diameter as the body 8 of the tube shown in Figure 8, ll the bellows folds which extend outwardly from the normal diameter of the body 9, I I the annular shoulder and t2 the annular lateral flange. These last two portions have not been disturbed or changed by the operation which forms the bellows folds.

The shoulder H has the function of locating the bellows in its assembly and may be called the locating shoulder. Both the locating shoulder II and the flange H are of greater diameter than the outside diameter of the bellows folds or convolutions and both the shoulder II and flange I! are integral with the body of the bellows.

In the production of an article of this construction it is very dimcult to accomplish the end without a great amount of loss and breakage, but by subjecting the cup and the tube to the sequence andplurality of operations described commercial bellows may readily be made on a successful production basis.

What I claim is:

1.'I'he method of producing flexible metallic bellows which includes drawing a blank successively until a tube of the desired length is obtained, then successively reducing the body portlon of the tube without reducing the open end thereof so that the latter forms a large cup end, then forming a portion of said cup end in the form of a lateral outwardly extending annular flange and then forming a plurality of bellows folds or convolutions in said body portion whereby a metallic bellows is formed having a locatins shoulder and annular flange at its open end.

2. The method of producing flexible metallic bellows of relatively small diameter and having a comparatively large number of bellows folds or convolutions, which includes subjecting a metal blank to a plurality of drawing operations until" a tube of the desired dimensions is obtained, subjecting the body of the tube to a plurality of reducing operations without reducing the open end of the tube whereby a large cup end is provided with an annular shoulder, forming a part of the large cup end into a lateral outwardly ex-a tending annular flange and then forming a plurality of bellows folds or convolutions in the body of said tube. 3. The method of making flexible metallic bellows which includes drawing a blank until a tube of proper dimension is obtained, reducing part of the tube until a body portion of the desired length and diameter is obtained with a large cup at its 'open end to form an annular shoulder,

forming the outer portion of said large cup end wardly to form a lateral annular flange, and then forming a pluralityof bellows folds or convolutlons in the reduced body portion to produce a flexible metallic bellows havinga locating shoulder and an annular flange at its open end.

5. A method of producing flexible, expansible and contractible metallic bellows, which includes drawing a blank into tubular form, then reducing H the body portion of the tubular blank without reducing the open end portion thereof so as to form a large cupped end and a shoulder, flaring out the cupped end to form an outwardly extending flange, and then forming a plurality of bel 

